Abstract
Purpose :
Myopia severity has a profound impact on visual impairment in later life. A patient’s final level of myopia may be lowered by myopia control, but also by delaying onset. Here we evaluate the influence of age of onset on the final recorded level of myopia.
Methods :
Data were extracted from the following reports:
● two prospective cohort studies of myopia progression in East Asia where final recorded level of myopia is presented as a function of age of onset (Chua et al., 2016; Hu et al., 2020)
● two retrospective studies of myopia progression in India and the Netherlands (Verkicharla et al., 2004; Polling et al., 2021)
● two cross-sectional studies in Argentina and the UK (Iribarren et al., 2004; Williams et al., 2013).
For the above, age of onset was based on self-report of age at first spectacle prescription and the midpoint was used for all age ranges.
A seventh set of data comprised Finnish subjects originally recruited for a clinical trial and followed into adulthood (Parssinen et al., 2019). Subjects were divided into five groups according to age at recruitment which was used as a surrogate for age of onset.
Results :
Figure 1 shows the final recorded level of myopia as a function of age of onset for the seven studies. Figure 1A shows data for the two East Asian studies. The myopia level is different because the reference ages are 11 and 17 years. The slopes are 0.97 and 0.68 D/year, meaning that each year later age of onset is associated with 0.97 or 0.68 D less myopia at the final refraction. Figure 1B shows data for the five non-East Asian studies. For four studies the slopes are substantially flatter, with slopes between 0.23 and 0.35 D/year. In contrast, the slope for the Finnish study was 0.87 D. Among subjects of European descent, increasing age of final refraction tended to be associated with higher levels of myopia.
Conclusions :
Among East Asians, delaying onset of myopia by just one year has potential to lower the final level myopia by 0.75 D or more—equivalent to multiple years of myopia control with existing modalities. The benefit is lower, but meaningful, among non-East Asians. The trend linking age of final refraction with final myopia level suggests ongoing adult progression.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.